Polishing-roll for photographic burnishers



(No Model;)

A. H. HUMPHREY.

POLISHING ROLL FOB PHOTOGRAPHIG BURNISHERS. No. 596,268. Patented Dec.28,1897.

WITNESSES: INVENTOI? m: Momma versus cu. PNOTO-LITNO. wAsuwnYom-o. c

UNITED STATES PATENT OFFICE.

ALFRED H. HUMPHREY, OF KALAMAZOO, MICHIGAN.

POLISHING-ROLL FOR PHGTGGRAPHEQ BURNISHERS.

SPECIFTCATION forming part of Letters Fatent No. 596,268, dated December28, 1897.

Application filed January '7, l 892.

To all whom it may concern..-

Be it known that I, ALFRED l-I. l-IUMPHEEY, a citizen of the UnitedStates, residing at Kalamazoo, in the county of Kalamazoo and State ofMichigan, have in vented certain new and useful Improvements in theManufacture of Hollow Polishing-Rolls for PhotographicBurnishing-Machines, of which the following is a specification.

My invention has for its object the production of a hollow roll for aphotographic burnishing machine which shall be of light Weight, uniformthickness, and the polishingsurface of which shall be dense and smooth.

Heretofore in this class of machines the rolls have been made from castmetal, and, as is well known, the surface of a piece of cast metalinvariably contains a greater or less number of sand-holes and isnecessarily rough and uneven andalso more or less porous. Again, incasting a hollow roll it is practically an impossibility to get theshell of uniform thickness. This irregularity in the thickness causesthe roll to become heated much more quickly in one part than another,and in this class of work it is absolutely necessary that a uniform heatbe maintained throughout the entire polishing-surface of the roll.Again, in this class of machinery the rolls are necessarily very closetogether, and the irregularity in the thickness of the roll, and theconsequent heating of one part more quickly than another, prevents auniform contraction and expansion, and consequently the roll is veryoften warped and pressed out of shape by contact with the other roll.Again, the cast roll must, in order to have the requisite strength, haveits shell cast with a greater or less amount of metal in it, and as theheat must be applied to the interior of the roll the interior diameterof the roll cannot be reduced beyond a certain point, although it isdesirable to have the exterior diameter as small as possible. To obviatethese various difficulties, I make the roll of wrought metal, such asawrought-iron pipe or tube or steel pipe or tube. This enables me toobtain a hollow roll with an extremely thin shell and at the same timeone which is absolutely uniform in its thickness.

The metal composing it is much more dense Serial No- 41'7,321. (N0model) and smoother than the cast metal, while the interior diameterremains the same.

In the drawings, Figure 1 is a side elevation of my roll and a portionin section and without the orifices at the end. Fig. 2 is a sideelevation showing the orifice for the admission of air to the interiorof the roll. Fig. 3 is an end elevation.

In carrying out the invention, A represents a tube of the desireddiameter. This tube is first swaged, rolled, or otherwise treated toreduce its ends, as shown at a, to form spindles for the roll. Afterthis rolling or swaging process, if desired, the roll may be struck bysuitably-shaped dies to bring it to the requisite form.

I would have it understood that the process whereby the ends of therolls are reduced to form the spindles is immaterial, the essentialfeature being to have the entire roll and spindles formed of a singlepiece of wrought metal. After the spindles have been formed the orificesa may be drilled or otherwise formed in the beveled or tapered ends ofthe roll, as shown in Figs. 2 and 3. The polishing-surface of the rollis then smoothed and polished to the necessary degree.

It will thus be observed that by forming the rolls and spindles of asingle piece of wrought metal I have obtained a roll with a shell thatis comparatively thin, and consequently one that can be readily heatedfrom the interior, one which will heat uniformly throughout itspolishing-surface, one which is of light weight, one in which theexpansion and contraction of the metal will be uniform throughout, andone having a perfectly smooth and dense polishing-surface.

What I claim is In a polishing-roll for photographic burnishing-machinesconsisting of a tube provided 011 each end with a spindle or a journalcontaining apertures 011 the shouldered portion between the journal andthe roll; said tube and spindle being made of a single piece of wroughtmetal substantially as described.

ALFRED H. HUMPl-IREY.

Witnesses:

EDWIN W. DE Yon, SAMUEL S. SKINNEE.

